"KBCW, digital channel 45 (virtual channel 44), is a CW-affiliated television station based in San Francisco, California. KBCW is owned by the CBS Corporation. The station's signal is transmitted from Sutro Tower."

KBCW began as an independant station called KBHK, which stood for Kaiser Broadcasting/Henry Kaiser, in 1968. It was sold Field in 1977 which in turn sold the station to United Television in 1983. From 1995 to 2006, KBHK was a UPN owned-and-operated station after United Television partnered with UPN. On January 24th, 2006, it was announced that UPN and WB would combine to form a new fifth television network, The CW, in September. On the day the new network was announced, it signed a ten-year affiliation deal with 11 of CBS' UPN stations, including KBHK. To reflect the new affiliation, KBHK officially changed to KBCW.

Fun fact: Several key scenes from the Robert Redford movie, The Candidate, were filmed in KBHK's studio at 420 Taylor Street. Many of KBHK's technicians appeared in the movie as themselves.

-taken from wikipedia